Sagging eye syndrome (SES), first described by Rutar and Demer in 2009, is a cause of acquired, small-angle horizontal and vertical strabismus that most often occurs in elderly patients [1].
My client was post-IOL with subsequent diplopia, diagnosed as 4th nerve palsy (CT not MRI due to metal in ear) and was referred to a surgeon. Second opinion from neuro-ophthalmologist found Sagging Eye Syndrome. Rx'd spectacle lenses with 6 PD vertical.

https://webeye.ophth.uiowa.edu/eyefo...agging-eye.htm